CLINICAL CORE ? CORE B: PROJECT SUMMARY/ABSTRACT The BIOCARD study is a longitudinal, observational study of 349 individuals who were cognitively normal and primarily middle aged (mean age=57.1) at enrollment. The subjects have now been followed for up to 27 years. The overall objectives of the project are to further advance the study of preclinical Alzheimer?s disease by: (1) clarifying the pattern and rate of change in AD biomarkers (including those based on CSF, blood, MRI, and PET imaging) and cognition; the biomarkers to be studied include several promising novel biomarkers derived from blood, CSF and brain imaging. (2) maximizing our data by working collaboratively with several research groups who have comparable data, and (3) providing a publicly accessible data, brain scans, and biological specimens, for researchers in the field. To accomplish these goals we established 7 Cores and, with this application, are also including 2 projects. The Clinical Core (Core B) has a wide range of responsibilities related to the evaluation and follow-up of the subjects in the BIOCARD study. The specific aims include: (1) screening and enrollment of the new study participants, (2) scheduling subjects for all visits and all study procedures, (3) completion of the annual clinical and cognitive assessments and consensus diagnoses, and accompanying subjects to all additional study procedures, (4) acquisition of ante-mortem autopsy approval, (5) assistance with subject retention activities, (6) analysis of the clinical and cognitive data and working with other Cores and Projects to integrate the clinical and cognitive data into their analyses, and (7) working with the Informatics Core to assure that the clinical and cognitive data shared with outside investigators is as accurate as possible.